Remove scrollbar width/height computations from layout.

sky/engine/core/rendering/RenderLayerScrollableArea.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 100 matching lines @@
 
     virtual bool updateAfterCompositingChange() override;
 
     bool hasScrollbar() const { return m_hBar || m_vBar; }
 
     LayoutUnit scrollWidth() const;
     LayoutUnit scrollHeight() const;
     int pixelSnappedScrollWidth() const;
     int pixelSnappedScrollHeight() const;
 
-    int verticalScrollbarWidth(OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
-    int horizontalScrollbarHeight(OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const;
-
     IntSize adjustedScrollOffset() const { return IntSize(scrollXOffset(), scrollYOffset()); }
 
     void paintOverflowControls(GraphicsContext*, const IntPoint& paintOffset, const IntRect& damageRect, bool paintingOverlayControls);
     void positionOverflowControls(const IntSize& offsetFromRoot);
 
     LayoutRect exposeRect(const LayoutRect&, const ScrollAlignment& alignX, const ScrollAlignment& alignY);
 
     // Returns true our scrollable area is in the FrameView's collection of scrollable areas. This can
     // only happen if we're both scrollable, and we do in fact overflow. This means that overflow: hidden
     // layers never get added to the FrameView's collection.
@@ skipping 63 matching lines @@
     IntPoint m_cachedOverlayScrollbarOffset;
 
     // For areas with overflow, we have a pair of scrollbars.
     RefPtr<Scrollbar> m_hBar;
     RefPtr<Scrollbar> m_vBar;
 };
 
 } // namespace blink
 
 #endif // RenderLayerScrollableArea_h